The present invention relates to a lockable lever arm assembly for use with a mechanical leverage system mounted on a frame, such as the frame of a vehicle, to move an implement between a lowered position and a lifted position.
An implement is broadly defined as a tool or an instrument operatively connected to the frame of another object or structure, such as a vehicle. These implements are usually vertically movable between a lowered position and a lifted position. The lowered position generally corresponds to a ground-engaged position in the context of a vehicle.
The implements found on vehicles are typically used for cultivating, cutting grass or hay, plowing snow or earth, cleaning pavement, etc. Their size is generally proportional to that of the corresponding vehicle. Large implements require powerful lifting mechanisms provided with a hydraulic actuator. However, smaller implements may only require a lifting mechanism using the muscular force of the operator as the power source. Such implements are generally found on all-terrain vehicles (ATV) or garden tractors. Portable industrial devices may also be provided with a lifting mechanism of this kind. A lift handle is made accessible to the operator and the vertical position of the implement is changed by changing the position of the lift handle.
Conventional small lifting mechanisms have more or less complicated arrangements for maintaining an implement in the lifted position against its own weight. For instance, some use a toothed rack while others use a side locking pin that holds the lift handle in place. These locking mechanisms require that the operator pushes a button or moves the lift handle sidewards to lock it at or release it from its lifted position.